From: "Allen J. Hainer"
" What is the recommended pitching concentration? How fast does a liquid
"yeast package reach this concentration? I always thought that yeast reached
"a particular concentration and leveled off, can only a few ounces of
"starter solution reach a high enough yeast concentration so that it results
"in the "recommended" concentration when added to 5 gallons of wort?

Yeast does grow to about 10 million cells/ml and then levels off. The
liquid yeast pouches are too small to provide enough yeast to reach
this level without a significant lag period. Professional brewers grow
yeast in volumes that increase about 20 fold at each step. So for a 5
gallon batch, you ought to be pitching about a quart starter. For this
to be the correct rate, your quart needs to have reached the 10^7
level, which is at high krausen.

The right way to handle the foil pouches is to make a starter. It
isn't very difficult and you need only plan your brew a few days
ahead. Here are two methods:

--- Quick and Dirty ---
If you are going to brew on the weekend, pop the pouch on Thursday
morning before going to work. That evening, boil 2 cups of dry extract
in half a gallon of water with a couple pellets of hops. Treat it as
if you were making a full batch of beer--boil it an hour or so. Add
water if it gets too low. Turn off the heat and let it settled for a
few minutes. Get a wine jug and run hot water over and in it, so that
it won't be shocked and break. Slowly pour your still hot wort into
the bottle, leaving behind as much of the trub and hops as you can.
Put some foil over the top and put it in your freezer. In about 2
hours it'll be cold enough to pitch your ballooned foil pouch. At that
point, put an airlock on it and leave it until you brew. On Saturday
you'll have a quart of beer in high krausen and a very short lag
period.

--- The Right Way ---
At your next brew session, make 6 gallons of wort instead of 5. Put
the remainder into 4 quart mason jars and go through a normal boiling
water canning. Do this by putting the tops on the jars and gently
tightening the bands. Put the jars into a pot of boiling water with a
rack on the bottom--don't put the jars directly on the pot--with enough
water to cover them. Wait 15 minutes after the pot comes back to a
boil. Remove the jars and let them cool. The bands will be loose and
the tops sealed. If you can press the lid down, it didn't seal. Once
you have prepared this, you are ready to start 4 batches of beer: open
a jar of wort and pour it into a sanitzed bottle. Add the yeast and
close with an airlock.

As with any other brewing procedure, it always seems to take more effort
to describe it than to do it.